A highly severe path traversal vulnerability (CVE-2026-48282) in the web application development platform Adobe ColdFusion, which could lead to remote code execution, has been discovered and confirmed to be **actively exploited in attacks within just hours of its disclosure**. The U.S. CISA (Cybersecurity and Infrastructure Security Agency) has added this vulnerability to its 'Known Exploited Vulnerabilities Catalog' and has instructed federal agencies to take immediate action. Organizations operating internet-facing ColdFusion servers must apply patches immediately and check for signs of system compromise.
Vulnerability Overview and Scope of Impact
CVE-2026-48282, recently disclosed, is a path traversal vulnerability (CWE-22) in the FILEIO handler of Adobe ColdFusion's Remote Development Services (RDS). If exploited, an unauthenticated remote attacker can write files to arbitrary locations on the server by sending specially crafted HTTP requests.
Specifically, if a malicious ColdFusion Markup Language (CFML) template is placed in a web-accessible directory (such as the web root), its execution could allow arbitrary OS commands to be run with the privileges of the web server.
Affected versions are ColdFusion 2025 Update 9 and earlier, as well as ColdFusion 2023 Update 20 and earlier.
Specific Impacts and Attack Scenarios
Exploitation of this vulnerability occurs in environments where ColdFusion's RDS function is enabled and authentication is disabled. An attacker can leverage this configuration weakness to upload malicious files and cause the ColdFusion server to execute them, leading to the following potential scenarios:
1. **Server Takeover via Web Shell Placement**: An attacker uploads a web shell and gains full control over the server through it. This can enable theft of confidential information, data tampering, system destruction, and lateral movement to other systems.
2. **Data Leakage**: Reading arbitrary files on the server, such as database credentials or configuration files, could lead to the leakage of confidential information.
CISA has confirmed that this vulnerability was exploited in real-world attacks shortly after its disclosure, warning that a wide range of systems are likely at risk.
Immediate Actions for Engineers
Adobe released security updates addressing this vulnerability on June 30, 2026. Please implement the following countermeasures immediately.
1. **Update Adobe ColdFusion**: If you are using an affected version, immediately update to ColdFusion 2025 Update 10 or ColdFusion 2023 Update 21.
2. **Verify and Disable/Restrict RDS Functionality**: If Remote Development Services (RDS) is not needed, disable it or restrict access to only trusted IP addresses.
3. **Additional Defense at the Web Server Level**: If ColdFusion is running behind a web server (e.g., Nginx, Apache), it is recommended to strengthen configurations to prevent path traversal attacks and unauthorized file uploads. The following is an Nginx example; consider configuring your web server accordingly. This does not directly fix the ColdFusion vulnerability but is effective as part of a defense-in-depth strategy.
location ~* /(\.\./|%2e%2e/|%2e%2e\) {
deny all;
return 403;
}
# Webルート内の実行不可能なディレクトリへの不正なスクリプトアップロードと実行を防止
location ~* /(uploads|images|media)/.*\.(cfm|php|jsp|asp|aspx)$ {
deny all;
return 403;
}4. **Investigate for Signs of Compromise**: Even after updating, investigate whether unauthorized files (such as web shells) have been uploaded to ColdFusion's web root or `/CFIDE/` directory, and check logs for suspicious access to confirm the absence or presence of compromise.
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